A commonly available split fluorescent lamp, such as a G23 or G24 plug-in type fluorescent lamp, is adapted for use in various light fixtures and generally comprising a lamp tube having a pluggable lamp cap and a lamp base adapted for engaging with the pluggable lamp cap and coupling with a ballast mounted in a light fixture. Under normal circumstances, the ballast in the light fixture can last for 5˜6 times longer than the lamp tube such that replacement of used lamp tube needs to be done for a couple of times during its lifetime. While replacing the used lamp tube with a new one which is however usually having operation parameters not in prefect match with that of the original ballast whereby rendering the lifespan of the new lamp tube to be shortened. Further, it is extremely inconvenient to replace or repair the ballast in the light fixture when the ballast is found to be faulty during its operation as the dismantling of the same is rather difficult. Though such split fluorescent lamp might be replaced by a regular integrated compact type fluorescent lamp, but the original illumination effect of the light fixture cannot be maintained without adaptive adjustment in the original design of the light fixture and such adjustment will bring additional cost and is thus somewhat uneconomical.